Observation of Ferroelectricity in Paramagnetic Copper Octacyanomolybdate

We report the observation of ferroelectricity in a copper octacyanomolybdate-based paramagnet, Cu2[Mo(CN)8]·8H2O (CuII, S = 1/2; MoIV, S = 0). This compound has a freezing point for the fixation of hydrogen bonding at 150 K. Around this temperature, an enhancement in the ferroelectricity and an increase in the dielectric constant are observed. The ferroelectricity of this system is classified into amorphous ferroelectrics; i.e., the electric poling effect induces an electric polarization. The electric polarization is maintained by the structural local disorder of hydrogen bonding and the three-dimensional CN network. In this ferroelectricity, the crystal structure is a polar group of C∞v after application of an electric field

Super-Ionic Conductive Magnet Based on a Cyano-Bridged Mn–Nb Bimetal Assembly

A two-dimensional manganese-octacyanoniobate based magnet, MnII3[NbIV(CN)8]2(4-aminopyridine)10(4-aminopyridinium)2·12H2O, was prepared. This compound shows a spin-flip transition with a critical magnetic field value of ca. 200 Oe, which originates from metamagnetism. In addition, an impedance measurement indicates that this compound is a super-ionic conductor with 4.6 × 10–4 S cm–1. The observed super-ionic conductivity is explained by the proton conduction (so-called the Grotthuss mechanism) through the hydrogen-bonding network, i.e., Lewis acidity of the Mn ion accelerates the deprotonation of the ligand water molecules, and then the released proton propagates via ligand water molecules, noncoordinated water molecules, and 4-aminopyridinium cations

Super-Ionic Conductive Magnet Based on a Cyano-Bridged Mn–Nb Bimetal Assembly

A two-dimensional manganese-octacyanoniobate based magnet, Mn^II₃[Nb^IV(CN)₈]₂(4-aminopyridine)₁₀(4-aminopyridinium)₂·12H₂O, was prepared. This compound shows a spin-flip transition with a critical magnetic field value of ca. 200 Oe, which originates from metamagnetism. In addition, an impedance measurement indicates that this compound is a super-ionic conductor with 4.6 × 10^–4 S cm^–1. The observed super-ionic conductivity is explained by the proton conduction (so-called the Grotthuss mechanism) through the hydrogen-bonding network, i.e., Lewis acidity of the Mn ion accelerates the deprotonation of the ligand water molecules, and then the released proton propagates via ligand water molecules, noncoordinated water molecules, and 4-aminopyridinium cations

Zero Thermal Expansion Fluid and Oriented Film Based on a Bistable Metal-Cyanide Polymer

A zero thermal expansion (ZTE) material based on plate-shaped rubidium manganese hexacyanoferrate, Rb_0.97Mn­[Fe­(CN)₆]_0.99·0.3H₂O, is prepared using a polyethylene glycol monolaurate (PEGM) surfactant matrix. The prepared microcrystals show a charge transfer induced phase transition between the cubic Mn^II–NC–Fe^III and tetragonal Mn^III–NC–Fe^II phases. The Mn^III–NC–Fe^II phase exhibits a small negative thermal expansion (NTE) along the <i>a</i>_LT and <i>c</i>_LT axes with a thermal expansion coefficient of α₍<i>a</i>_LT) = −1.40 ± 0.12 × 10^–6 K^–1 and α₍c_LT) = −0.17 ± 0.13 × 10^–6 K^–1 over a wide temperature range of 15 K – 300 K. Such small |α| materials are classified as ZTE materials. The far-infrared spectra show that NTE originates from the transverse modes δ­(Fe–CN–Mn) of the transverse translational mode around 304 cm^–1, and transverse librational modes at 253 and 503 cm^–1, which are assigned according to first principle calculations. Molecular orbital calculations indicate that ZTE and the charge transfer phase transition both originate from the transverse mode. Additionally, an oriented film on SiO₂ glass is prepared using a microcrystal dispersive methanol solution and a spin-coating technique. This is the first example of a ZTE film that maintains a constant film thickness over a wide temperature range of 300 K

High Proton Conductivity in Prussian Blue Analogues and the Interference Effect by Magnetic Ordering

High Proton Conductivity in Prussian Blue Analogues and the Interference Effect by Magnetic Orderin

Hyaluronic acid promotes proliferation and migration of human meniscus cells via a CD44-dependent mechanism

Purpose: Treatment of meniscal injury is important for osteoarthritis (OA) prevention. Meniscus cells are divided between inner and outer cells, which have different characteristics and vascularity. We evaluated the effects of hyaluronic acid (HA) on the proliferation and migration of human inner and outer meniscus cells, and investigated the underlying healing mechanisms. Materials and Methods: Lateral menisci from 18 patients who underwent total knee arthroplasty were used. Meniscus cells were harvested from the outer and inner menisci and evaluated using migration and proliferation assays after treatment with HA or chondroitin sulfate (CS). The effects of HA on prostaglandin E2 (PGE2)-induced apoptosis and gene expression were evaluated. Results: Cell migration and proliferation were increased by HA in a concentration-dependent manner, in both inner and outer meniscus cells. PGE2-induced apoptosis and caspase-3/7 activity were suppressed by HA in both inner and outer meniscus cells, and these effects were blocked by an anti-CD44 antibody. COL2A1 and ACAN mRNA levels were upregulated following HA treatment of inner meniscus cells. MMP13 mRNA was downregulated following CS stimulation of both inner and outer meniscus cells. These results suggest that CS treatment suppresses the inflammatory reaction rather than providing meniscal restoration. The phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways were activated by HA in both types of meniscus cells; these effects were blocked by treatment with an anti-CD44 antibody. Conclusions: HA promoted human meniscus regeneration by inhibiting apoptosis, promoting cell migration, and accelerating cell proliferation, potentially through the PI3K/MAPK pathway via the CD44 receptor.</p

Direct Observation of Magnetic Domain and Magnetization Reversal on Prussian Blue-Based Magnetic Films

Knowledge of the magnetic domain is indispensable for understanding the magnetostatic properties of magnets. However, to date, the magnetic domain has not yet been reported in the field of molecule-based magnets. Herein, we study the magnetic domains of molecule-based magnets. Two magnetic films of iron/chromium hexacyanidochromate FexCr1–x[Cr(CN)6]2/3·5H2O (x = 0; Film 1 and x = 0.2; Film 2) were prepared for investigation. The temperature evolution of surface magnetization was measured using magnetic force microscopy. Film 1 showed a magnetic domain below Curie temperature (TC) and its positive-magnetic polarization increased monotonously with decreasing temperature, while Film 2 showed positive magnetic polarization below TC and switches from positive to negative magnetization through a demagnetization state at 146 K. This study originally reports the temperature variation of the magnetization state at the magnetization reversal. The magnetic domains appeared as a maze pattern with an approximate domain size of one-to-several micrometers. This work shows that research on molecule-based magnets can be expanded from magnetochemistry to the magnetostatic engineering of bulk magnets, molecule-based magnetostatic engineering

Proton Conductive Luminescent Thermometer Based on Near-Infrared Emissive {YbCo₂} Molecular Nanomagnets

Lanthanide­(III)-based coordination complexes have been explored as a source of bifunctional molecular materials combining Single-Molecule Magnet (SMM) behavior with visible-to-near-infrared photoluminescence. In pursuit of more advanced multifunctionality, the next target is to functionalize crystalline solids based on emissive molecular nanomagnets toward high proton conductivity and an efficient luminescent thermometric effect. Here, a unique multifunctional molecule-based material, (H5O2)2(H)­[YbIII(hmpa)4]­[CoIII(CN)6]2·0.2H2O (1, hmpa = hexamethylphosphoramide), composed of molecular {YbCo2}3– anions noncovalently bonded to acidic H5O2+ and H+ ions, is reported. The resulting YbIII complexes present a slow magnetic relaxation below 6 K and room temperature NIR 4f-centered photoluminescence sensitized by [Co­(CN)6]3– ions. The microporous framework, built on these emissive magnetic molecules, exhibits a high proton conductivity of the H-hopping mechanism reaching σ of 1.7 × 10–4 S·cm–1 at 97% relative humidity, which classifies 1 as a superionic conductor. Moreover, the emission pattern is strongly temperature-dependent which was utilized in achieving a highly sensitive single-center luminescent thermometer with a relative thermal sensitivity, Sr > 1% K–1 in the 50–175 K range. This work shows an unprecedented combination of magnetic, optical, and electrical functionalities in a single phase working as a proton conductive NIR-emissive thermometer based on Single-Molecule Magnets

Proton Conductive Luminescent Thermometer Based on Near-Infrared Emissive {YbCo₂} Molecular Nanomagnets

Lanthanide­(III)-based coordination complexes have been explored as a source of bifunctional molecular materials combining Single-Molecule Magnet (SMM) behavior with visible-to-near-infrared photoluminescence. In pursuit of more advanced multifunctionality, the next target is to functionalize crystalline solids based on emissive molecular nanomagnets toward high proton conductivity and an efficient luminescent thermometric effect. Here, a unique multifunctional molecule-based material, (H5O2)2(H)­[YbIII(hmpa)4]­[CoIII(CN)6]2·0.2H2O (1, hmpa = hexamethylphosphoramide), composed of molecular {YbCo2}3– anions noncovalently bonded to acidic H5O2+ and H+ ions, is reported. The resulting YbIII complexes present a slow magnetic relaxation below 6 K and room temperature NIR 4f-centered photoluminescence sensitized by [Co­(CN)6]3– ions. The microporous framework, built on these emissive magnetic molecules, exhibits a high proton conductivity of the H-hopping mechanism reaching σ of 1.7 × 10–4 S·cm–1 at 97% relative humidity, which classifies 1 as a superionic conductor. Moreover, the emission pattern is strongly temperature-dependent which was utilized in achieving a highly sensitive single-center luminescent thermometer with a relative thermal sensitivity, Sr > 1% K–1 in the 50–175 K range. This work shows an unprecedented combination of magnetic, optical, and electrical functionalities in a single phase working as a proton conductive NIR-emissive thermometer based on Single-Molecule Magnets

DS_10.1177_0363546519850578 – Supplemental material for Evaluation of Meniscal Regeneration in a Mini Pig Model Treated With a Novel Polyglycolic Acid Meniscal Scaffold

Supplemental material, DS_10.1177_0363546519850578 for Evaluation of Meniscal Regeneration in a Mini Pig Model Treated With a Novel Polyglycolic Acid Meniscal Scaffold by Shuhei Otsuki, Kosuke Nakagawa, Tomohiko Murakami, Shunsuke Sezaki, Hideki Sato, Masakazu Suzuki, Nobuhiro Okuno, Hitoshi Wakama, Kunihiro Kaihatsu and Masashi Neo in The American Journal of Sports Medicine</p